The critical charge density of 4H-SiC thyristors

The critical charge density which determines the maximum voltage ramp (dV/dt) of a thyristor, the minimum value of the gate control current, and the parameters of current filamentation has been determined in SIC thyristors both theoretically and experimentally, For 4H-SiC thyristors blocking 300 to 400 V, the critical charge density has been found to be 2 x 10(15) cm(-3) and 10(14) cm(-3) at a forward voltage of 5 and 100 V, respectively for an operating temperature of 560 K, The critical current density j(0) below which the turn-on state is localized has also been estimated theoretically and experimentally, While theoretical calculations predict its value to be 2 x 10(2) A/cm(2), experimental results show a range of 3 x 10(2) to 7.6 x 10(2) A/cm(2).